Apparatus for gasification of wood



June 5, 1951 c. E. JENKINS 2,556,090

APPARATUS FUR GASIFICATION oF woons Filed Nov. 2, 1945 2 sheets-sheet 1 ff 6 i 26 Fzt'y. I.

ATTORN EY'S June 5, 1951 c. E. JENKINS 2,556,090

APPARATUS FOR GAsIFIcATIoN oF woons Filed Nov. 2, 1945 2 Sheets-Sheet 2 INVENTOR CZarenceEI Jenlfzns ATTORNEYS dnnen-.end

Patented June 5, 1951 UNITED STATES PATENT OFFICE 2,556,090 APPARATUS FOR GASIFICAIIO-N OF WOD Clarence E..Jenkins`,`Keene, N. H.

Application November 2, 1945, `Serial' No. 626,258

This invention relates .to the generation of gas from. wood and wood substances such as 'wood IChips, fragments, pieeeaor particles, .including .stalks and corn cops, although harder .wood sub.-

stances are preferred.

-Inasmuch as the `invention n ncls its maximum usefulness .on woods commonly Aused `as ruelle, it ywill be specifically .described in connection with `the generation of .gas from wood chips, but `this Lisby `way of illustration.

It is of .course well known .in the art to generate .fuel gases from charcoal, and generally ihQIn various .wood subtances, but units heretofore,conH structed for .use .with .natural wood, as ,distinguished fromcharcoal, produce distillates orrcondensable .vapors .which are .apt to detiiinentally affect or Vchoke the producer, or .the .gas pipes and burners, or require .elaborate .gas cleaning means that must themselves .be periodically cleaned. All such apparatus is undesirable, espe- 'cially for `snoall units .designed for theme .use .in

regions where wood is plentiful andl .other fuels are costly, `inaccessible, or not readily available.

`It is an object `of the .present invention coprovide a producer of relatively cheap .and simple construction, especially applicable, though not limited to, sizes `for `domestic: use, which .idoanot tend to `become lfouled or clogged .with ,conden- `sates `and distillates, and which have .a :relatively `high Agas production per volume of yfuel used.

"To this end rny invention provides a producer and method of operating the same wherein the wood, periodically charged into the producer, is

vprogressively distilled and reduced itc charcoal i .line II--II of Figi;

1Fig.;3 is a fragmentary section .of rthe lower part of the producer opened for rthe discharge of ash;

Eig. 4 `is-a fragmentary bottom planview on ,angenlarged scale `of a portion of the i-nletV air 12 Claims. (Cl. V48-r'76) ,Fia .51s a fragmentary verdeel section in the plane of line V-Vof Fig. 4.

In the draWingsfZ designates a cylindricaLrnetal shell, which typically may be from l2 to 1li `inches in diameter. .It is provided .with e :top cover 3 hung .from e Yhinged .olernhinahar `il, .there beine a bolt and Wins not oesemhlydaione end of this har `for holding the ooyer dow-n and applying pressure to it: .the .hinge for he har vloeing designated at 6. 'I he covershould ire a tight seal with the body under .normal-.operatine conditions, .but it may be opened .from time to time .to ohargeeddiiionel wood into. the reto-rfi :shaft I2. the lower portion of Whiohis threaded,

and which has Xed to its .tono Curved as dior or `ashrake I3, which as shown in Fig. radially extending curved arms whichserye the rake ,is rotated in a clockwise direction, :to rnove the ashes encountered thereby htoirlard tl'1e center perforate area.

On the lower end of the shaft lis a iedxoollar I4 with ratchet teeth l5 on its upper end, `this collar being keyed Ato lthe shaft. the shaft between the collar and the upper ,end

Threaded "on `of the `shaft is a hub or nut `element .lr6 ,with ratchet .teeth l1 `on its lower end andv with a truncated conical peripheral surface lll: ifrom which extend downwardly and .outwardly pro- .,jectingspokes I9 that join to a rim .prringl When the `threadedpollar is in =the upperposition shown in Fig. l, its conical Vsurfac'zemakes -a sealing -contact with .the lower edge Aof tu'liewash discharge cone J0, but using `the rim or .ring lZ0 as a hardwheel, the nut .may befscrevre'd down on the shaft until its ratchet .teeth .mesh with v,those on .the collar 14 (see ,Figi 3) so that (the ash agitatorcr rakelndy thenherotated. ,Atthis Atime the Abottom of .the cone "L0 is .fopen so that the ashes will `fau ont, `tut .they .fail ,between vthe spokes I91 andnot ontothe hands of :theoperator who is holding the ,ring 20. There is .thus proyided a uniqudseal and ash .remover thai-@irnposes on 4the operator a minimum .of ,consious eiort Ain opening the ash drop, ,shakingvthe ashes Iand then closing it. i

l.secured to the Shell 2 near the `too is az-fitting Fig. 1.

2i into which is entered and from which is hung a curved gas off-take pipe 22, the pipe curving from the fitting outwardly and downwardly, its length below the curve being substantially coincident with the vertical axis of the shell. There is a pipe 23 connected to the fitting 2l outside the producer, this pipe having a T connection 24 therein with a waste pipe 25 leading therefrom, there being a valve 26 in this pipe. There is also a service pipe 2i connected into the T, the service pipe having a valve 28 therein.

Concentrically positioned about the vertical lower portion of the gas olf -take pipe 22 is an air inlet pipe 29 having a radial connection 3U at its top which connects to a fitting 3l on the shell, giving increased rigidity to the axial concentric pipe arrangement. the off-take pipe and air inlet duct are in heat exchanging relation. The lower end of the air duct or pipe 29 opens into a distributor 32,V this distributor having an upper plate or disk' 33, a sealing ring or flange 34, a bottom plate 35, with a wind chamber 35 between the two plates. The gas off-take pipe passes through the wind chamber and opens through the bottom plate 35. Near the periphery of the distributor the bottom plate has small holes 3l bored diagonally therethrough, all of the holes sloping in the same direction, so that the air discharged from the openings blows downwardly and tangentially to create a cyclone or vortex under the distributor.

The distributor is spaced above the bottom of the shell several inches. It is considerably smaller in diameter than the shell so that fuel can feed down past it, but should be large enough to avoid a relatively cold area being present in the vfuel bed remote from the distributor.

There is an air supply pipe 38 connected to the fitting 3| outside the generator, this pipe connecting to a small power driven blower 39. There is a T connection in pipe 38 with a down leg connected to flexible or resilient tube 4U, which for example may be copper tubing, there being Aa hand valve lil at the top of this tube where it joins the T. On the lower end of the tubing l there is an igniter comprising a tube 42 slidably entered and sealed in an opening Ythrough lthe shell of the generator at a level just below the distributor. It has a removable screw-plug `43 at its outer end. By reason of the limited flexibility or resilience of the air supply tubing 40 the igniter may normally assume theposition shown in Fig. l, but to start the producer, it is pushed in to the dotted line position in which the inner end of the igniterV is then adjacent the .lower face of the distributor.

YThe operation and preferred method of operating may now be followed. Assume that there is no charge in the shell and the generator is just being put into use. Charcoal is rst charged :into the generator to about the level of the disgenerator, it will be obstructed at the center by vthe distributor disk and will repose in such a `manner as to leave an inverted conical space below the distributor. This is indicated Yat A in The igniter tube 42 is pushed in to the dotted line position of Fig. 1 so that its inner end just enters the chamber under the distrib Also, with the arrangementV utor. The screw plug 43 is removed, and a lighted taper is inserted. Y

With the blower 39 in operation, valve 4l is opened and plug d3 is put back in the end of the igniter tube. There will be sufficient back pressure in the distributor so that much of the air will blow through the ignitor tube, and the fuel surrounding the inverted conical space will quickly come to incandescence.

During this starting period, service line valve 28 is closed and vent line valve 26 is opened, so that the air and starting gases are vented. Ash drop cone I8 is of course closed.

After the combustion has been well started, valve 4I is closed, shutting off air to lthe igniter tube, which is then pulled back to its normal position. All of the incoming air then enters the generator through the inclined holes 3l of the distributor, creating a whirl or vortex of air in the space A and forming a zone of intense heat in the wall of fuel immediately surrounding this space. Only the outermost air in this swirl is contacting the fuel, and as oxidation occurs, the CO2 gas that is formed passes out through the fuel bed and in so doing is converted to CO. It moves out to a cooler portion of the fuel mass. Some of it swirls downwardly and inwardly, rising through the center of the vortex and passes out pipe 22. Other portions of the gas rise through the fuel bed, driving out volatiles and causing the wood chips just above the combustion Zone to be reduced to charcoal. The gases thus rising through the chips and which are driven out of the chips form an eddy, apparently from the sides of the retort and downwardly near the center into the hottest part of the fuel bed, where the volatiles and gases burn upon contact with the incoming air. Only gases that have passed through the hot combustion zone and then swirl downwardly and inwardly can rise through the vortex in the space A and be carried off.

Pressures in the retort are slightly above atmospheric pressure to cause the gas to flow out the off-take pipe. The gas, after a period of operation is mostly CO, I-I, and N, although there is some CO2, CH4, some water vapor, and a trace of other condensates, but no tarry masses to clog Y the apparatus or required cleaning is needed. Preferably there is some vapor trap, not shown, in the service line to catch the small amount of water vapor and condensates that are formed. After the producer has been operating to make satisfactory gas, valve 26 to the waste line is closed and service pipe valve 28 is opened.

Thereafter the generator continues to'operate. The charcoal is gradually consumed to ash and drops down and new charcoal from above replaces it, and the cycle of distillation and producing charcoal continues. From time to time the producer may be opened to charge in fresh fuel and from time to time ashes are shaken from the bottom.

In operation the generator produces gas of good quality at a satisfactory rate and at high efficiency, the caloric value of the gas being high compared to the theoretical caloric content of the wood. It is observed, as the producer operates, that the space A does not remain uniformly centered under the off-take pipe, but tends to gyrate about the central axis, which is a highly desirable condition. t Y

The number of air holes in the distributor, the diameter of the distributor with reference to the diameter of the shell, and similar factors are attacco determined by experiment for 'each' Vparticular size of unit, but the relative proportions here shown and described have beenfound to be satisfactory. v

While lhave shown and described a'preferred embodiment of my invention, it will vbe understood that various changes and modifications may be made in this construction within the spirit of my invention.

I claim:

1. A wood gas producer comprising a fuel holder, a hollow disk-like member centrally and horizontally positioned in the fuel "holder spaced above the bottom thereof, said disk-like member having a chamber on the interior thereof and having inclined openings through the bottom face thereof near its periphery whereby air discharged from the chamber through Vthe openings is caused to swirl in the space under the disk-like member, means'for supplying airvunder pressure to said chamber, and means passing through the center lof the disk-like member for removing gases from the producer,

2. A wood gas producer comprising a fuel holder, a hollow disk-like member centrally and horizontally positioned in the fuel holder spaced above the bottom thereof, said disk-like member having a chamber on the interior thereof and having inclined openings through the bottom face thereof near its periphery whereby air discharged from the chamber through the openings is caused to swirl in the space under the disk-like member, means for supplying air under pressure to said chamber, and means passing through the center of the disk-like member for removing gases from the producer, `said means including an off-take pipe, said air supply means including a duct surrounding the off-take pipe.

3. A wood gas producer comprising a fuel holder, a, hollow disk-like member centrally and horizontally positioned inthe fuel holder spaced above the bottom thereof, said disk-like member having a chamber on the interior thereof and having inclined openings through the bottom face thereof near its periphery whereby air discharged from the chamber through the open- `ings is caused .to swirl in the space under the disk-like member, means for supplying air under pressure to said chamber, means passing through the center of the disk-like member for removing gases from the producer, a radially movable igniter tube passing through the holder and sealed therein adapted to have its terminal project from a point adjacent the wall of the holder to a point adjacent the under side of the periphery of said member, and means for selectively causing air under pressure to circulate through the igniter tube.

4. A wood gas producer comprising a fuel holder having a bottom'therein, the bottom having a central ash discharge opening therein, a shaft passing through said opening with an agitator on the upper end thereof, the lower portion of the shaft being threaded, a conical member threaded on the shaft movable upwardly to close the ash discharge opening, and means on the lower part of the shaft for cooperation with said conical member when the conicalmember is screwed down on the shaft for causing the shaft to rotate with the conical member.

5. A wood gas producer comprising a hollow, cylindrical, vertical fuel holder, a distributor element in the fuel holder near the bottom thereof but spaced above the bottom, said distributor being of disk-like form and having a diameter 6". substantially less than the `interior diameter' of the holder whereby fuel in the holder may'gravitate downwardly past the distributor and repose at an angle under the distributor to form Aan inverted generally conicalpocket, means onthe under face "of the distributor for discharging air into the pocket in a tangential direction to produce a swirl of air, and means `for removing gas from the region ofthe center of the pocket.

6. A gas generator of the class described comprising a casing having a vertical chamber therein through which fuel maymove by'gravty, an air inlet distributor in the chamber spaced from the walls thereof and spaced above the bottom thereof, the distributor having openings therein through which air may be projected into the space beneath it in a downward and tangential direction, means for supplying inlet air to the distributor, the distributor being constructed to obstruct the downward feeding of fuel in the portion of the chamber immediately above it whereby to form an open space under the distributor, and means opening into said space for removing gases therefrom.

7. `A gas generator of the class described cornprising a casing having a vertical chamber therein through which fuel may move by gravity, an air inlet distributor in the'chamber spaced from the walls thereof and spaced above the bottom thereof, the distributor having openings therein through which air may be projected into the space beneath it in a downward and tangential direction, means for supplying inlet air to the distributor, the distributor being constructed to obstruct the downward feeding of fuel in the portion of the chamber immediately above it wherebyV to form an open space under thedistributor, and means opening into said space for removing gases therefrom, there being concentric inlet and outlet pipes for the air and gases respectively which are in heat exchanging relation.

8. A wood gas producer comprising a fuel holder, means including a horizontally disposed ange suspended in the holder for creating a substantially centrally located pocket in the lower portion of the fuel mass in the holder when the holder is charged with fuel, said nange having' an air supply chamber therein, a conduit connecting said chamber with a source of supply, said flange having a plurality of peripheral openings with their upper ends in communication with said air supply chamber and their lower ends terminating on the underside of said flange, said openings being so constructed and arranged as to create a downwardly projected swirl of air in said pocket rotating about the central axis of the holder, and gas Withdrawal means positioned substantially centrally of the underside of said flange for removiner gas from the central portion of the swirl of air.

9. A wood gas producer comprising a fuel holder, means including a horizontally disposed flange suspended in the holder for creating a substantially centrally located pocket :in the lower portion of the fuel mass in the holder when the holder is charged with fuel, said. flange having an air supply chamber therein, a conduit connecting said chamber with a source of air supply, said flange having a plurality of peripheral openings with their upper ends in communication with said air supply chamber and their lower ends terminating on the underside of said flange, said openings being so constructed,

'and arranged as to create a downwardly projected swirl of air in said pocket rotating about the cene tral axis of the holder, and gas withdrawal means positioned substantially centrally of the underside of said flange for removing gas from the central portion of the swirl of air, said Withdrawal means comprising a conduit extending upwardly and axially through said flange.

VA,10. A wood gas producer comprising a fuel holder, means including a horizontally disposed .flange suspended in the holder for creating a substantially centrally located pocket in the lower. portion of the fuel mass in the holder when the holder is charged with fuel, said flange having an air supply chamber therein, a conduit connecting said chamber with a source of air supply, said flange having a plurality of peripheral openings with their upper ends in communication with said air supply chamber and vtheir lower ends terminating on the underside of said flange, said openings being so constructed and arranged as to create a downwardly projected swirl of air in said pocket rotating about the central axis of the holder, gas withdrawal means positioned substantially centrally of the underside of said flange for removing gasA from the central portion of the swirl of air, and an igniter having its inner end movable toward and away from said pocket.

11. A wood gas producer comprising a fuel holder, means including a horizontally disposed flange suspended in the holder for creating a substantially centrally located pocket in the lower portion of the fuel mass in the holder when the holder is charged with fuel, said flange having an air supply chamber therein, a conduit connecting said chamber with a source of air supply, said flange having a plurality of peripheral openings with their upper ends in communication with said air supply chamber and their lower ends terminating on the underside of said flange, said openings being so constructed and arranged as to create a downwardly projected swirl of air in said pocket rotating about the central axis of the holder, gas withdrawal means positioned substantially centrally of the underside of said flange for removing gas from the central portion of the swirl Vof air, and an igniter having its inner end movable .toward andaway from said pocket, said, igniter comprisinga tubehaving a movable plug at its outer endrand means for selectively forcing'air into the ignter.

12. A gas generator comprising a shell having a fuel holding chamber therein, a distributor in the shell for supplying air to the interior of the chamber, said distributor comprisinga horizontally disposed flange spaced from the bottom and sides of the shell, the distributor flange having an air supply chamber therein and having peripheral openings with their upper ends in communication with said supply chamber and their lower ends terminating on the underside of Vthe flange, said openings being so constructed and arranged as to form a swirlof air concentrically within the shell immediately below said flange and aboutv the vertical axis of the shell, and gas withdrawal means positioned substantiallycentrally of the underside of said flange for removing gases from the fuel chamber at the top center of said swirl.

CLARENCE E. JENKINS.

' REFERENCES CITED following references are of record in the ille of this patent:

` UNITED STATES PATENTS Number Name Date -Re. 4,961 `Schuyler July 2, 1872 ,Y 2,376,149 Kalle May 15, 1945 27,445,327 Keith July 20, 1948 i 2,459,344 Y Sepulchre Jan. 18, 1949 FOREIGN PATENTS YNumber Country `Date Y 113,236l Australia June 1941 V134,296 'Austria May 15, 1945 V"247,200 Germany May 23, 1912 -501,166 Great Britain Feb. 22, 1939 557,468 Great Britain Nov. 22, 1943 '558,825 Great Britain Jan. 24, 1944 `687,942 France Aug. 14, 1930 l OTHER REFERENCES 

1. A WOOD GAS PRODUCER COMPRISING A FUEL HOLDER, A HOLLOW DISK-LIKE MEMBER CENTRALLY AND HORIZONTALLY POSITIONED IN THE FUEL HOLDER SPACED ABOVE THE BOTTOM THEREOF, SAID DISK-LIKE MEMBER HAVING A CHAMBER ON THE INTERIOR THEREOF AND HAVING INCLINED OPENINGS THROUGH THE BOTTOM FACE THEREOF NEAR ITS PERIPHERY WHEREBY AIR DISCHARGED FROM THE CHAMBER THROUGH THE OPENINGS IS CAUSED TO SWIRL IN THE SPACE UNDER THE DISK-LIKE MEMBER, MEANS FOR SUPPLYING AIR UNDER PRESSURE TO SAID CHAMBER, AND MEANS PASSING THROUGH THE CENTER OF THE DISK-LIKE MEMBER FOR REMOVING GASES FROM THE PRODUCER. 